Add debugging code for simulating packet loss in outgoing UDP packets. The

algorithm for dropping packets is a modified two state algorithm for creating
bursts of dropped packets. As configured there is about a 1.5% drop rate.

Invocation of the packet loss code is commented out by default.
mb-throttle-test
Mic Bowman 2014-12-29 12:02:36 -08:00
parent bb82076a4d
commit e71549a2cb
1 changed files with 66 additions and 0 deletions

View File

@ -107,6 +107,62 @@ namespace OpenMetaverse
/// </summary>
public float AverageReceiveTicksForLastSamplePeriod { get; private set; }
#region PacketDropDebugging
/// <summary>
/// For debugging purposes only... random number generator for dropping
/// outbound packets.
/// </summary>
private Random m_dropRandomGenerator;
/// <summary>
/// For debugging purposes only... parameters for a simplified
/// model of packet loss with bursts, overall drop rate should
/// be roughly 1 - m_dropLengthProbability / (m_dropProbabiliy + m_dropLengthProbability)
/// which is about 1% for parameters 0.0015 and 0.15
/// </summary>
private double m_dropProbability = 0.0030;
private double m_dropLengthProbability = 0.15;
private bool m_dropState = false;
/// <summary>
/// For debugging purposes only... parameters to control the time
/// duration over which packet loss bursts can occur, if no packets
/// have been sent for m_dropResetTicks milliseconds, then reset the
/// state of the packet dropper to its default.
/// </summary>
private int m_dropLastTick = 0;
private int m_dropResetTicks = 500;
/// <summary>
/// Debugging code used to simulate dropped packets with bursts
/// </summary>
private bool DropOutgoingPacket()
{
double rnum = m_dropRandomGenerator.NextDouble();
// if the connection has been idle for awhile (more than m_dropResetTicks) then
// reset the state to the default state, don't continue a burst
int curtick = Util.EnvironmentTickCount();
if (Util.EnvironmentTickCountSubtract(curtick, m_dropLastTick) > m_dropResetTicks)
m_dropState = false;
m_dropLastTick = curtick;
// if we are dropping packets, then the probability of dropping
// this packet is the probability that we stay in the burst
if (m_dropState)
{
m_dropState = (rnum < (1.0 - m_dropLengthProbability)) ? true : false;
}
else
{
m_dropState = (rnum < m_dropProbability) ? true : false;
}
return m_dropState;
}
#endregion PacketDropDebugging
/// <summary>
/// Default constructor
/// </summary>
@ -117,6 +173,10 @@ namespace OpenMetaverse
{
m_localBindAddress = bindAddress;
m_udpPort = port;
// for debugging purposes only, initializes the random number generator
// used for simulating packet loss
// m_dropRandomGenerator = new Random();
}
/// <summary>
@ -395,6 +455,12 @@ namespace OpenMetaverse
{
// if (IsRunningOutbound)
// {
// This is strictly for debugging purposes to simulate dropped
// packets when testing throttles & retransmission code
// if (DropOutgoingPacket())
// return;
try
{
m_udpSocket.BeginSendTo(